/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.response;

import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.response.SolrQueryResponse;
import org.apache.solr.search.DocSlice;
import org.apache.solr.common.SolrDocumentList;

public class PageTool {
	private long start;
	private int results_per_page = 10;
	private long results_found;
	private int page_count;
	private int current_page_number;

	public PageTool(SolrQueryRequest request, SolrQueryResponse response) {
		String rows = request.getParams().get("rows");

		if (rows != null) {
			results_per_page = new Integer(rows);
		}
		// TODO: Handle group by results
		Object docs = response.getValues().get("response");
		if (docs != null) {
			if (docs instanceof DocSlice) {
				DocSlice doc_slice = (DocSlice) docs;
				results_found = doc_slice.matches();
				start = doc_slice.offset();
			} else {
				SolrDocumentList doc_list = (SolrDocumentList) docs;
				results_found = doc_list.getNumFound();
				start = doc_list.getStart();
			}
		}

		page_count = (int) Math.ceil(results_found / (double) results_per_page);
		current_page_number = (int) Math
				.ceil(start / (double) results_per_page)
				+ (page_count > 0 ? 1 : 0);
	}

	public long getStart() {
		return start;
	}

	public int getResults_per_page() {
		return results_per_page;
	}

	public long getResults_found() {
		return results_found;
	}

	public int getPage_count() {
		return page_count;
	}

	public int getCurrent_page_number() {
		return current_page_number;
	}

	@Override
	public String toString() {
		return "Found " + results_found + " Page " + current_page_number
				+ " of " + page_count + " Starting at " + start + " per page "
				+ results_per_page;
	}
}
